Subjects of the Framingham Heart Study will be investigated serially by simultaneous recording of Lead II Electrocardiogram, Phonocardiogram and Carotid Displacement pulse waves. From these, heart rates and the Systolic Time Intervals will be calculated, viz.: Electromechanical Systole, Pre-Ejection Period, q-Im time, Isovolumic Contraction Period, Left Ventricular Ejection Time and Central Pulse Transmission Time. These will be compared with the clinical data obtained independently by Heart Study clinicians to determine their individual and combined screening value.